On Donnerstag, 29. November 2007, hyc(a)symas.com wrote:
> Full_Name: Ralf Haferkamp
> Version: All
> OS: Linux, glibc 2.7
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (188.8.131.52)
> Newer versions of glibc (2.7) in my case might return duplicate addrinfo
> structs in the results under certain circumstances. According to the
> friendly glibc maintainer ;) this is not a bug:
> Unfortunately he doesn't give a reason for this change in behavior.
Interesting. In that bug report the /etc/hosts file has 127.0.0.1 once and
::1 once, so why is 127.0.0.1 being returned twice? That is clearly bogus.
glibc code explicitly checks the /etc/hosts entry for IN6_IS_ADDR_LOOPBACK
and returns the the in_attr_t for INADDR_LOOPBACK in that case. For reasons
that the glibc author seemingly doesn't want to share with the outer world.
> BTW, I didn't find any reference in the related RFCs that
state that the
> getaddrinfo results need to be unique (nor the opposite).
> In my current builds I simply patched slapd to check the getaddrinfo()
> results for uniqueness in the slap_get_listner_addresses() function. Has
> anybody a better idea how to fix this?
I'm sure there's nothing that states that the returned info is required to
be unique. The returned data must accurately reflect the host databases
being queried though. If you put "127.0.0.1 localhost" twice in /etc/hosts,
then it's reasonable to get it returned twice. But if it's only in there
once, then returning it twice is a bug.